18.00: Police made a new statement on progress in their investigation.

Read it here. Police said they were looking at the suspect's mental health, his link to right-wing extremist organisations, and that anti-terror officers were involved. They did not announce charges. They also praised the 77-year old man who tried to stop the killing of Cox. "During the course of the incident a 77-year-old man bravely intervened to assist Jo and in doing so sustained a serious injury to his abdomen and although now stable he remains in hospital," police said.

16:23: Police find Nazi material in the home of Cox's alleged killer

Special police units that searched the property of the suspect, named locally as Thomas mair, found Nazi regalia and far-rightwing literature, according to The Guardian.

16:16: The Green party is not "inclined" to stand in the Batley and Spen by-election

The Green Party has said that it is unlikely to contest the upcoming Batley and Spen by-election but has not officially ruled it out. The death of MP Jo Cox means that her constituency will need to elect a new representative. The Conservatives and UKIP said that they will not contest the seat in respect of Cox's public service.

The Green Party said in a statement:

The Green party leadership is inclined not to stand in this election but we respect the right of our local party to meet and agree their position with their members. They will be doing this over the coming days. In the meantime we continue to pay our respects to Jo Cox and send our sincere and heartfelt condolences to her family.

15:51: Vigils are being held nationwide this evening

At least 20 vigils will be held across the country this evening in memory of Jo Cox. Leeds, not far from where the MP was killed, will hold one at 1900 p.m, as will Manchester and Birmingham. London's will take place at 1930 p.m.

Reuters

15:15: Police are investigating white supremacist group for social media posts glorifying the murder of Jo Cox

The Guardian is reporting that a white supremacist group National Action is under Police investigation for posts that appeared on one of the group's social media accounts.

The Guardian's Kevin Rawlinson is reporting that a "wealth" of material glorifying the killing was posted online by far-right supporters — including a tweet saying "only 649 MPs to go."

15:06: Jo Cox's final words were 'my pain is too much'

Jo Cox's last words were "my pain is too much," according to Gulham Maniyar, the father of Cox's assistant Fazila Aswat who was with the Labour MP during the attack on Thursday.

Maniyar told ITV news:

She was with my daughter. They'd left Batley office, they were in the marketplace, she was in my daughter's car sitting in the back seat. The car stopped and Jo decided to come out. My daughter didn't know she'd been shot. Because this person must be waiting outside where the surgery happens.

She said her [Jo's] injury was so bad and she was in her arms. There was lots of blood. She said 'Jo, get up' but she [Jo] said 'no, my pain is too much, Fazila'. And I think those were the last words Jo spoke. She could not do anything else. She tried to comfort her. Then the police came, the air ambulance came, they took her to hospital. She was a witness and her clothes were full of blood.

Reuters

15:01: Lib Dems will NOT contest the Batley and Spen by-election

The Liberal Democrats have just announced that the party will not stand in the upcoming Batley and Spen by-election out of respect for Cox's public service. The Conservatives and UKIP have said the same.

14:56: Prosecutors are 'considering' what charges to bring against the suspect

As things stand, prosecutors are "considering" what charges to bring against the 52-year-old man who was arrested following the attack, believed to be local man Thomas Mair.

In a statement, the Crown Prosecution Service said: "The special crimes and counter terrorism unit at the Crown Prosecution Service is considering what charges should be brought against a suspect held over the death of Labour MP Jo Cox.

"The unit is led by Sue Hemmings and has been in discussions with detectives investigating the case."

Following the killing of Cox, Police and parliamentary authorities are now reviewing politicians' security, according to the Financial Times, but the number of threats received by MPs in recent years is staggering and the abuse received by Cox is far from an isolated incident.

David Cameron and Jeremy Corbyn gave powerful speeches earlier today. Here are some extracts from both.

Cameron: "Today our nation is rightly shocked. And I think it is a moment to stand back and think about some of the things that are so important about our country. The fact that we should treasure and value our democracy, where members of parliament are out in the public, accountable to the public, available to the public, and that's how Jo died. She died doing her job."

Corbyn: "She was a truly wonderful woman. I'm deeply sorry, deeply sad at what has happened to her and my condolences to all the people of Batley and Spen who she represented so well, and, of course, to her wonderful family, her husband, her children and all of her wider family."

Now, some more on Thomas Mair's alleged links to the US-based neo-Nazi National Alliance.

The group's founder, William Pierce, penned a novel that was described as "the Bible of the racist right" called The Turner Diaries. It inspired a number of atrocities including the Oklahoma bombing which killed 168 people in 1995.

The UK Independence Party has just announced that it will not be standing in the Batley by-election, according to Buzzfeed's Jim Waterson. We are yet to hear from the Greens and Liberal Democrats.

13:58: Cameron and Corbyn lay flowers for Jo Cox

Here is a clip of David Cameron and Jeremy Corbyn laying flowers at the memorial, courtesy of the BBC.

13:54: Parliament will be recalled on Monday for tributes to Jo Cox

Labour leader Jeremy Corbyn has just confirmed that David Cameron and Commons speaker John Bercow have accepted his request to have parliament recalled on Monday for members of the house to pay tributes to Jo Cox.

13:50: David Cameron and Jeremy Corbyn standing side by side paying tribute to Jo Cox in Birstall, West Yorkshire

Prime Minister David Cameron and Labour leader Jeremy Corbyn have arrived together in Birstall to lay flowers in honour of Jo Cox.

Sky News

13:37: Anti-racism groups call for criminal investigation into Britain First

Anti-racism groups Unite Against Fascism (UAE) and Stand up to Racism have called for far-right political party Britain First to be investigated for criminal and terrorist activity. In a joint statement released in the last minutes, they said:

We cannot allow double standards in response to such attacks, especially now that information has come to light linking Thomas Mair to neo-Nazi terrorist and white supremacist groups. Jo Cox's murderer shouting 'Britain first' must be treated in exactly the same fashion as someone shouting 'ISIS' and carrying out a similar attack. This incident cannot be treated as an isolated incident by someone with mental health problems. Britain First and the paramilitary 'Britain First Defence Force' must be investigated for terrorist and criminal activity.

The full joint statement can be read below.

13:19: Cameron and Corbyn will make joint appearance in Birstall today

David Cameron will pay tribute to Jo Cox alongside opposition leader Jeremy Corbyn later today, the Guardian reports. The pair is currently travelling to West Yorkshire.

12:58: The Conservative party will not be contesting the Batley and Spen by-election

Downing Street has just said that the Conservative party will NOT be contesting the upcoming by-election in Batley and Spen to fill the vacant seat left by Cox.

This announcement comes shortly after the party's former chair Grant Shapps said that parties other than Cox's Labour should not contest the seat out of respect for the MP's public service.

12:49: PM to visit Batley and Spen today to pay respects

Prime Minister David Cameron will visit Batley and Spen today to pay his respects to Jo Cox, according to The Sun's Tom Newton Dunn.

12:14: "We have lost one of us," says Jo Cox's former headteacher

Mike Cook, the headteacher of Heckmondwike Grammar School where Jo Cox was head girl, just paid tribute to the MP. Speaking to The Guardian, he said:

The school is grieving collectively for Jo and there's a very strong sense of community in our school. Although Jo was 41 and the oldest children in our school we have in school are 18, they clearly consider that we have lost one of us. One of our community, a local girl, [who] made the opportunity of all the opportunities that the school presented in her time here. Just as the current crop do. There is a sombre mood, filled with respect for everything that Jo has achieved. Deeply saddened that she won't be able to carry on making that impact that she had clearly begun to do. There is very very low mood in school today.

MP Mary Creagh places flowers in Market Square after the murder of Jo Cox, 41, Labour MP for Batley and Spen, who was shot and stabbed by an attacker at her constituency on June 16, 2016 in Birstall, England.
Christopher Furlong/Getty Images

11:53: West Yorkshire Police expect to release a statement this afternoon

A spokesperson for West Yorkshire Police just told Business Insider over the phone that they expect to release another statement at some point this afternoon.

11:39: The by-election to fill Cox's seat should not be contested, says Grant Shapps

Former Conservative party chair Grant Shapps has said that the election to fill the seat left by Jo Cox should not be contested by parties other than Labour out of respect for the tragic circumstances of the MP's death.

A one-off by-election will be held to elect someone to fill the vacant seat of Batley and Spen, in accordance with parliamentary rules. However, Shapps tweeted on Thursday saying that Cox's replacement should be elected unopposed as a mark of tribute to her work and public service.

11:25: A man who wasn't Mair was arrested in March for sending Cox abusive messages

The Metropolitan police have just confirmed that an unnamed man was arrested in March this year after Cox complained about abusive messages. However, the man arrested was not Thomas Mair.

In a statement Scotland Yard said:

Officers received an allegation of malicious communications from Jo Cox MP, and in March 2016 arrested a man in connection with the investigation. The man subsequently accepted a police caution. The man who accepted the police caution is not the man in custody in West Yorkshire.

11:15: Thomas Mair bought Nazi and white supremacist literature, as well as a guide on how to make a gun

More on Thomas Mair's links to the neo-Nazi National Alliance:

The Southern Poverty Law Center (SPLC) published receipts suggesting that Mair bought £436 ($620) worth of literature which advocates the creation of an all-white homeland and the total eradication of Jews.

Business Insider's Matthew Nitch Smith goes into more detail in this article.

11:05: Jeremy Corbyn: "The whole of the Labour family are devastated tonight."

Labour leader Jeremy Corbyn has just published a video tribute to Jo Cox on Twitter. He said:

The whole of the Labour family are devastated tonight. Jo Cox has been killed doing her duty, doing her work as a constituency MP. She is somebody who dedicated her life to human rights and to justice. She worked for anti-slavery campaigns, she worked for Oxfam, and she became an MP for the area where she was born and grew up and loved.

Listen to the Labour leader's tribute in full:

10:50: Canadian politician pays emotional tribute to Cox

The tragedy of Jo Cox's death has been felt around the world. Nathan Cullen, a Canadian MP who met Cox when engaged in humanitarian work abroad, paid a very emotional tribute to the Labour MP in Canadian parliament on Thursday and received a standing ovation.

Watch Cullen's tribute:

10:26: Police considered extra protection for Cox after months of abusive messages

Police were considering giving Cox special protection because she had been receiving abusive messages for at least three months, according to The Times Newspaper.

The report added that extra security was being considered at her constituency surgery in Birstall close to where the attack took place and her houseboat in London. There is no suggestion that the abusive messages and the attack were linked, however.

10:20: Mair was a "dedicated supporter" of a neo-Nazi group in the US

On Thursday night, the Southern Poverty Law Centre reported on its website that the alleged attacker, Tommy Mair, was a supporter of the neo-Nazi National Alliance. The organisation, which tracks hate groups, said that Mair bought a manual from the US far-right group in 1999 that included a guide on how to build a pistol.